Contact arrangement for vacuum switches

ABSTRACT

A contact arrangement comprises two inner contacts which can be moved relatively to each other, and two immovable outer contacts. The inner contacts comprise a contact carrier and a contact piece, and the outer contact comprises a contact carrier and a ring-shaped high-current piece. The high-current contact pieces surround the contact pieces of the inner contacts and partially surround the contact carriers of the inner contacts and are spaced at a distance therefrom. The inner contact pieces are arranged eccentrically with respect to the longitudinal axis of the contact carrier at the latter, in such a way that a narrow gap will exist on one of the sides of the passage from the highcurrent contact piece to the contact carrier, between the inner contact pieces to the contact carrier, between the inner contact pieces and the high-current contact pieces, and the position of the inner contact can be firmly adjusted within an angular range of 0* through 30*, with respect to the passage. The high-current contact pieces are furthermore provided with a slot on the other side of the junction with the contact carrier. On one hand, the slots of the high-current contact pieces and, on the other hand, the inner contact pieces are arranged symmetrically opposite each other.

United States Patent 1191 Kuhl et al.

11 3,717,739 1 51 Feb. 20, 1973 1 1 CONTACT ARRANGEMENT FOR VACUUM SWITCHES [75] Inventors: Wilfried Kuhl, Grossschwarzenlohe; Leonhard Klug, Nuernberg, both of Germany [73] Assignee: Siemens Aktiengesellschaft, Berlin and Munich, Germany [22] Filed: April 4, 1972 [21] App]. No.: 241,036

[30] Foreign Application Priority Data April 13, 1971 Germany ..P 21 17 845.0

[52] US. Cl ..200/166 C, 200/144 B [51] Int. Cl. ..H0lh 1/06 [58] Field of Search ..200/166 C, 144 B, 146 R [56] References Cited UNITED STATES PATENTS 3,469,050 9/1969 Robinson et al. ..200/166 C 3,462,572 8/1969 Sofianek ..200/144 B 3,008,022 11/1961 Lee ..200/144 B 3,591,742 7/1971 Hundstad..... ....200/166 BH 3,592,987 7/1971 Lempert ..200/166 C Primary Examiner-H. 0, Jones Attorney-Benjamin H. Sherman et al.

[57] ABSTRACT A contact arrangement comprises two inner contacts which can be moved relatively to each other, and two immovable outer contacts. The inner contacts comprise a contact carrier and a contact piece, and the outer contact comprises a contact carrier and a ringshaped high-current piece. The high-current contact pieces surround the contact pieces of the inner contacts and partially surround the contact carriers of the inner contacts and are spaced at a distance therefrom. The inner contact pieces are arranged eccentrically with respect to the longitudinal axis of the contact carrier at the latter, in such a way that a narrow gap will exist on one of the sides of the passage from the highcurrent contact piece to the contact carrier, between the inner contact pieces to the contact carrier, between the inner contact pieces and the high-current contact pieces, and the position of the inner contact can be firmly adjusted within an angular range of 0 through 30", with respect to the passage. The highcurrent contact pieces are furthermore provided with a slot on the other side of the junction with the contact carrier. On one hand, the slots of the high-current contact pieces and, on the other hand, the inner contact pieces are arranged symmetrically opposite each other.

7 3 Claims, 3 Drawing Figures fast after the arc in the contact pieces. The firmly adjusted within CONTACT ARRANGEMENT FOR VACUUM SWITCHES DESCRIPTION This invention relates to a contact arrangement for vacuum switches comprising two inner contacts which can be moved relatively to each other and two enveloping and immovable ring-shaped high-current contact pieces, wherein the contact pieces are attached to the contact carriers and are positioned opposite to each other,-and wherein the inner contact pieces and 'the outer contact pieces are electrically connected with each other via their contact carrier and connection pieces. I

It is known that the effect of move the light are at the magnetic fields which place of a magnetic loop on the contact piece surfaces in a corresponding direction are utilized for supporting the extinguishing properties in vacuum switches. Such a light are movement is required for breaking currents, for example above 2,000 A, in order to avoid an excessive material bumup at the contact pieces, as well as to produce a smaller amount of metal vapors so that the contact-break distance in the contact gap recovers again sufficiently zero axis crossing of the current half wave has been attenuated.

Contact arrangements are known which are embodied as double contacts and which comprise two inner contacts which are relatively movable with respect to each other, and comprise two immovable outer contacts. In order to easily obtain a light-arc movement through the intrinsic magnetic field, the outer contacts are often provided with spiral-like or inclined slots. The slots are bridged by means of material sputters, as well as burning of thelight arc at the slot edges, which causes the magnetic power component to loose-efficiency for moving the light arc. By means of heating the wings at the outer contacts, the latter are bent due to fast switching processes caused by the opening and closing of the movable contacts, or even by the electrodynamic forces.

The invention is based on the task of providing a contact arrangement for vacuum switches wherein the difficulties as described above are avoided. The task is solved, according to the present invention, in such a way that the inner contact pieces are arranged eccentrically with respect to the longitudinal axis of the contact carriers at the latter, in such a way that a narrow gap exists on one of the sides of the passage from the high-current contact piece to the contact carrier, between the inner contact pieces and the high-current position of the inner contact can be 30 with respect to the passage. Furthermore, the highcurrent contact pieces are provided with a slot on the other side of the passage with the contact carrier, and on one hand, the slots of the high-current contact pieces, and on the other hand, the inner contact pieces are arranged symmetrically opposite each other.

The slots in the high-current contact pieces can, for example, extend at a right angle with respect to the frontal surfaces of the high-current contact pieces, and may touch their contact carriers at the passage to the high-current contact pieces. The slots, however, may also extend for example, at an inclination with respect to the frontal surfaces of the high-current contact an angular range .a of through 'er 7. The inner contact pieces, particularly in such a way that one of the ends of the slots touches the contact carrier at the passage to the high-current contact pieces. The other end of a slot is positioned in the area of the projection of the cross sectional surface of the contact carrier.

Other objects, features and advantages of the invention will be best understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view through a vacuum switch with a contact arrangement according to the invention;

FIG. 2 is a cross sectional view of the switch showing the contact arrangement according to this invention; and,

FIG. 3 shows the contact arrangement according to this invention in a perspective illustration.

FIG. 1 shows a longitudinal section of a vacuum switch of a type which is generally known in the art with a contact arrangement according to this invention, wherein the double-contact construction has been utilized, which is known in general per se. This is a construction consisting of inner and outer contacts and in which the inner contacts are surrounded by and spaced at a distance from the outer contacts. The inner contacts are composed of the inner contact pieces 1 and 2, respectively, and the respective-contact carriers 3 and 4. The outer contacts comprise ring-shaped high-current contact pieces 5 and 6, respectively, and the con tact carriers 7 and 8, respectively. The high-current contact pieces 5 and 6, respectively, are provided with a respective slot. The slots are not illustrated in this figure (compare FIGS. 2 and 3). The slots are respectively disposed on one side of the passage from the contact carrier to the high-current contact piece. The inner contact pieces 1 and 2, respectively, are arranged eccentrically with respect to the longitudinal axis of the contact carriers 3 and 4, at the latter. By means of this eccentric arrangement, and by means of a suitable geometric design of the respective contact pieces 1 and 2, a narrow gap (compare FIG. 2) is respectively formed between the inner contact pieces 1 and 2, and the respective high-current contact pieces 5 and 6. The position of the inner contacts 1, 2 can be firmly adjusted within an angular range a of 0 through 30", with respect to the side of the passage from the contact carriers 7 and 8, respectively, pieces 5 and 6, respectively, where no slot is positioned.

It has to be taken into account that, according to this invention, the narrow passages, on one hand, are symmetrically opposite each other after the final mounting process, and, on the outer hand, the slots also.

The inner contact piece 1 is electrically connected with the high current contactpiece 5 via the contact carrier 3, the connection piece 9 and the contact carripiece 2 is electrically connected with the high-current contact piece 6 via the contact carrier 4, the flexible connection piece 10 and the contact carrier 8. The contact carrier 4 can be moved, due to the metal bellows 15. A vapor screen 1 l prevents the formation of a conductive layer on the insulator member 12. The insulator member 12, may for example, consist of glass or ceramic and is connected with the end platesM via correspondingly formed parts 13.

to the high current contact,

The broken line 16 indicates the current path for currents up to several hundred amperes. With higher currents, the light arc L is forced radially towards the outside due to the intrinsic magnetic field and the eccentricity of the inner contact pieces 1 and 2, and displaced with respect to the high-current contact pieces 5 and 6. Here, the current feeding is effected via the concontacts 5 and 6.

A cross section through the vacuum switch shows the position of the narrow gap 17 between the inner contact piece 1 and the high current contact piece 5, in FIG. 2. The narrow gap 17 is staggered on one of the sides of the junction from the high-current contact piece 5 to the contact carrier 7, at the angle a. The slot 18 is provided in the high-current contact piece 5 on the other side of the contact carrier 7, in such a way that the slot 18 is barely tangent to the passage from the contact carrier 7 to the high-current contact piece 5. a right angle with respect to the frontal surfaces of the high-current contact piece 5. The broken line 19 indicates the direction of arc movement. Again, the reference numeral 1 is used for the inner contact piece 3, for the contact carrier for the inner contact piece 1, 11 for the metal screen and 12 for the insulator member.

In FIG. 3, the contact arrangement of this invention is shown in a perspective illustration. The inner contact piece 1 on the contact carrier 3 is surrounded by the slotted high-current contact piece 5 which is arranged on the contact carrier 7.

In this case, the slot 18 does not extend perpendicular to the frontal surfaces of the high-current contact piece 5, but at an angle of inclination with respect to the frontal surfaces, in such a way that one of the ends 20 of the slot 18 touches the contact carrier 7 at the passage to the high-current contact piece 5. The other end 21 of the slot 18 is positioned in the range of the projection of the cross sectional surface of the contact carrier 7. By means of the inclined embodiment of the is possibly arced over, netic loop is produced immediately by way of the contact carrier 7, due to the inclination of the slot, which again further drives the light arc in the same direction.

Although we have described our invention by reference to specifically illustrated constructions, many changes and modifications of our invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention; and it is to be understood that we intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly come within the scope of our contribution to the art.

We claim:

1. A contact arrangement in a vacuum switch of the type wherein two inner contact pieces which are movable relative to each other are surrounded by and associated with respective immovable ring-shaped high current contact pieces and the contact pieces are carried by respective contact carriers having longitudinal axes and arranged facing each other, the associated inner and outer contact pieces being electrically connected together via their respective contact carriers connection pieces, the lmprovement comprising means defining an eccentric projection of said contact carriers for said inner contact pieces and said inner contact pieces disposed and carried on the eccentric projections their respective contact carriers and thereby disposed cccentrically with respect to the longitudinal axes of said contact carriers to provide a narrow gap between each of said inner contact pieces and the associated ring-shaped high-current contact pieces and between the ring-shaped high-current contact pieces and the respective contact carrier of said inner contact pieces, said inner contact pieces being mounted for arcuate movement through an angular range of 030 with respect to said gap, and each of said ring-shaped high current contact pieces including means defining a slot opposite the respective gap, said slots arranged opposite each other and said inner contact pieces arranged opposite each other.

2. A contact arrangement according to claim 1 wherein said ring-shaped high current contact pieces include frontal surfaces, and said slots are perpendicular to the frontal surfaces and extend to their respective contact carriers in the area of the respective gaps. piece.

3. A contact arrangement according to claim 1, wherein said ring-shaped high current contact pieces include frontal surfaces, and each of said slots extend at an angle to said frontal surfaces, one end of said slot terminating at its respective contact carrier and the other end of said slot terminating in the area of a cross sectional projection of said contact carrier onto a frontal surface of said ring-shaped high current contact piece. 

1. A contact arrangement in a vacuum switch of the type wherein two inner contact pieces which are movable relative to each other are surrounded by and associated with respective immovable ring-shaped high current contact pieces and the contact pieces are carried by respective contact carriers having longitudinal axes and arranged facing each other, the associated inner and outer contact pieces being electrically connected together via their respective contact carriers and connectIon pieces, the improvement comprising means defining an eccentric projection of said contact carriers for said inner contact pieces and said inner contact pieces disposed and carried on the eccentric projections their respective contact carriers and thereby disposed eccentrically with respect to the longitudinal axes of said contact carriers to provide a narrow gap between each of said inner contact pieces and the associated ring-shaped high-current contact pieces and between the ring-shaped high-current contact pieces and the respective contact carrier of said inner contact pieces, said inner contact pieces being mounted for arcuate movement through an angular range of 0*-30* with respect to said gap, and each of said ring-shaped high current contact pieces including means defining a slot opposite the respective gap, said slots arranged opposite each other and said inner contact pieces arranged opposite each other.
 1. A contact arrangement in a vacuum switch of the type wherein two inner contact pieces which are movable relative to each other are surrounded by and associated with respective immovable ringshaped high current contact pieces and the contact pieces are carried by respective contact carriers having longitudinal axes and arranged facing each other, the associated inner and outer contact pieces being electrically connected together via their respective contact carriers and connectIon pieces, the improvement comprising means defining an eccentric projection of said contact carriers for said inner contact pieces and said inner contact pieces disposed and carried on the eccentric projections their respective contact carriers and thereby disposed eccentrically with respect to the longitudinal axes of said contact carriers to provide a narrow gap between each of said inner contact pieces and the associated ring-shaped highcurrent contact pieces and between the ring-shaped high-current contact pieces and the respective contact carrier of said inner contact pieces, said inner contact pieces being mounted for arcuate movement through an angular range of 0*-30* with respect to said gap, and each of said ring-shaped high current contact pieces including means defining a slot opposite the respective gap, said slots arranged opposite each other and said inner contact pieces arranged opposite each other.
 2. A contact arrangement according to claim 1 wherein said ring-shaped high current contact pieces include frontal surfaces, and said slots are perpendicular to the frontal surfaces and extend to their respective contact carriers in the area of the respective gaps. piece. 